title: Identification of Pseudomonas aeruginosa by pyocyanin production on Tech agar.
abstract: Pseudomonas aeruginosa is the only gram-negative bacillus capable of producing the very distinctive water-soluble pigment pyocyanin. We evaluated the reliability of this characteristic as a unique test for the identification of this organism by using Tech agar (BBL Microbiology Systems, Cockeysville, Md.) medium. A retrospective and prospective analysis was performed with a total of 835 strains of P. aeruginosa; 818 (98%) produced pigment within 48 h of incubation, and 96% of those which produced pigment were positive after overnight incubation. Seventeen strains (2.0%) failed to produce pigment; 15 were mucoid strains from patients with cystic fibrosis. Tech agar is an effective, simple, and inexpensive medium for P. aeruginosa identification and may be used as a unique test for all potential P. aeruginosa isolates (beta hemolytic on blood agar; lactose-negative, oxidase-positive colonies). Nonpigmented mucoid strains, as well as other nonpigmented organisms, will require additional testing to ensure proper identification.
mesh_terms: D001431:Bacteriological Techniques; D003470:Culture Media; D010619:Phenazines / Q000096:biosynthesis*; D011550:Pseudomonas aeruginosa / Q000145:classification* / Q000378:metabolism; D011710:Pyocyanine / Q000096:biosynthesis*
chemical_list: D003470:Culture Media; D010619:Phenazines; D011710:Pyocyanine